"check light" and functions.

[wriggz]

Anyone help....Turn on ign and the check light on the dash comes on flashes, depress the brake pedal and it stops,,sometimes on the journey the check light comes back on???? The over head check panel does not seem to work, light up on ign??? are there fuses for these or once gone, it needs replacing?..Checked the brake lights they work..so Dont know
2.The temp gauge flickers about almost like it is stuck..Somtimes in the blue then flicks to half way?? Is that the sender
Any answers to above greatfully recieved

[deian]

Hi,

Sounds like a bad battery on the SI board? When they come to the end of their life weird things can happen. Can anyone else confirm this?

[Chris-W]

Check light for the brakes stays on until you first use the brakes, when it can test the circuit. If it's coming on intermittently after that, check your brake light bulbs & sockets.

[wriggz]

The overhead check panel,,, would that be a straight replacement or something more synister?

[Brianmoooore]

The check light is supposed to flash until the brake pedal is first pushed, but the brake light LED on the overhead panel should be lit as well.
Do any of the other LEDs come on when they should and make the "check" light flash. Disconnect some relevant bulbs and see.
If things don't work, then it is usually the roof panel itself. Certainly nothing to do with the SI board.
If the light comes back on again when driving it points to an intermittant fault. If it's the brake lights causing it, then either a cheap out of spec lamp, a poor lamp connection, or a failing brake light switch.
Once a LED has been lit (on a fully working check unit), then it stays on untill reset by switching the ignition off and on, although the flashing check light can be extinguished by pressing the test button on the roof panel.

Temp gauge: tighten a small nut on the back of the cluster casing, directly behind the temp gauge.

[Brianmoooore]

PS: Duff SI board battery can also affect the temp gauge to some degree, along with other things, but if the service lights are behaving themselves, then the nut on the back is most likely.

[wriggz]

Thanx for the advice..One other thing...The "SI" board means nowt to me as I am new to the E30 Bm..Where is it, can it be replaced, how do you replace and how much?..Thta was more than one ...sorry

[Brianmoooore]

SI stands for service interval, and refers to the row of green LEDs plus a red and orange one that livr in the middle of the bottom of the instrument cluster, and tell you when the car is due for a service. Board also contains the electronics for the rev counter and a few other things.
The board has batteries on it to retain the memory if the main car battery is fitted. Broadly depending on whether the board is an early or late one, it will have either lithium non rechargeable batteries or rechargeable NiCd ones.
When these latter type get old and fail, they tend to short circuit, and pull down the voltage supply to the electronics, causing various problems. If the batteries are still not attended to, they will eventually leak corrosive liquid over the circuit board.

[wriggz]

Ah....well all the lights, (service ones) go on at ign...Are there any good techy books available that might assist, I suppose the Haynes ones are about, but are there any more?

[Brianmoooore]

Ah....well all the lights, (service ones) go on at ign..

Normal. What about after the engine is started?

Don't often see the words "good" and "Haynes" in the same sentance.

[wriggz]

They all go out once the engine is running....Waht I tend to do is switch the ign on, wait for the check light on the dash to flash then press the brake , it goes out....start the eng then drive.sometimes the check light comes back on..None of the o/head lights come on at all thro' proceedings,so I guess that is knackered..So if I get another one could that sort the fault providing of course that one aint knak'd...........There are some silly electrical faults..the ones metioned, and the front fogs and rear fogs dont work..I ve checked the fuses they seem ok, cant be all 4 bulbs,so with those faults, could that heve something to do with the check light??

[Brianmoooore]

Fogs are most likely the dual switch - responds well to dismantling cleaning and lubricating. Definitely nothing to do with the check light.
Do either of the dash warning lights come on?

One of more of the green LEDs should light when the engine is on, or the red and yellow.

[wriggz]

no dash lights come on.....all of the green light up....sorry bout this you must be bored now..

[robo]

I had a similar problem in that my temp gauge and speedo had stopped working altogether, although the flashing "check" light within the binnacle was seemingly unnafected at the time, (but had played up at another time previous - temporarily coming on for no apparent reason etc). I took the binnacle out, soldered some new solderable appropriate type batteries in there (got them from Maplins), and refitted the unit. Didn't do the trick, same symptoms. So I just got another whole binnacle from a scrappy, which did look nice & clean at the back, with its own existing batteries in there, took the speedo out, put mine in there and fitted the new binnacle unit back in my car. Job was a good un and have never had the problem since, which was about 18 months ago. I suspect that my problem was the batteries definitely - they did look a bit suspect, very dirty & old looking, although were not leaking, and also probably a loose/bad connection somewhere in the unit. I understand the batteries do last only a few years and will need replacing at some point.
Hope this helps, good luck.

[Brianmoooore]

If all the green Leds are lit with the engine running, then the SI indicator has been recently reset. (Whether it actually had the service is another matter of course). This suggests that the SI board and its batteries are OK.
No fog warning lights points towards switch

[Speedtouch]

The front fogs on my '88 325iSE didn't work, and it turned out both bulbs needed replacement and the dual switch cleaned out (fortunately fairly easy to do).

[robo]

The green led's should go off once running though Brian, eh? Cos mine never stay on once the engine is running, only come on with ignition lights lit to begin with (or yellow/red only, if all 5 green have disappeared over the 6 thousand miles or whatever the interval setting is) , then go off once engine started. When I had my problem with SI board etc, I seem to remember the green led's were not lit when engine running, as they are not when running now. Although the problem was well weird, I think the red/yellow can stay on whilst running, are you saying green could/do stay on even when engine is running, if there is a problem or not?

[Brianmoooore]

I had a similar problem in that my temp gauge and speedo had stopped working altogether, although the flashing "check" light within the binnacle was seemingly unnafected at the time,

Flashing check light is nothing to do with the cluster - it's just a bulb pushed into the back on flying leads. It's powered entirely by the panel in the roof.

As soon as the last green LED goes out with the engine running, the yellow will light............... I'm writing bollox here!
One or more green lights or the red and yellow light come on when you switch the ignition on. If it was green lights that come on, they will go out and remain out when the engine starts.
When the last green light has counted down and gone out, a yellow light will come on and remain on with the engine running. After a week or so, the yellow light will be joined by a red one.

[robo]

Nice one mate - I thought I had another problem there for minute! I dunno, what are we saddo's doing up at this hour talking turkey eh! Must be dedication, or something. I'm glad you are though.

Cheers

[ian332isport]

Don't often see the words "good" and "Haynes" in the same sentance.

Oi

[Nelly]

^^ LOL, don't worry Ian - i had a chuckle to myself as well when i saw that quote.

Neil.